Vertically oriented transportable container with improved stability

ABSTRACT

A transportable container apparatus includes an elongate container having a central axis and a base attached to a bottom end of the container. The container and base are substantially symmetrical about the central axis and the container is oriented substantially vertically with the base resting on a ground surface when in a working position. The container having an upper container section with upper walls substantially parallel to the central axis and a lower container section with lower walls substantially parallel to the central axis. The upper container section includes a sloping hopper at a bottom thereof to direct granular material into the lower container section. A floor of the container is sloped toward an outlet port defined in a ported wall of the lower container section such that granular material stored in the container slides down the floor to the outlet port.

BACKGROUND

This invention is in the field of transportable containers such as bins,tanks, or the like, and in particular such containers that arevertically oriented when installed at a work site and where stability isimproved

In many industries it is required to set up an array of equipment at atemporary work site, and then disassemble the installation, move it toanother work site, and re-assemble it. For example asphalt and concreteplants are often set up in locations where large quantities of materialare required for mad or building construction. Similarly well drillingrigs, such as those drilling for oil and gas, are set up at a drillinglocation, then taken down and moved to a different drilling location.

These portable plants and rigs typically include various tanks, bins,silos, and like containers for water, asphalt, sand, cement, and othermaterials such as might be required at any particular work site. Theseare transported to the work site, commonly in a lowered horizontaltransport orientation, and then raised to a vertical working orientationat the work site. These containers are typically transported to the worksite by flat-bed trucks or trailers in a lowered horizontal transportorientation. The trailer is maneuvered into position, and then thecontainer is raised from the horizontal transport position to a verticalworking position resting on the ground, and the trailer is moved awayfrom the site.

This vertical orientation reduces the ground area, or footprint,occupied by the installation. Also bins containing dry granular materialespecially are often elongated vertically when in a working position tomaximize the quantity of material stored above a hoppered bottom suchthat the granular material will flow out by gravity. Containers holdinggranular material typically have a hoppered bottom with walls slopingtoward an outlet port at the bottom of one side of the container so thatall the material inside will flow out through the outlet port, leavingthe container empty.

The outlet port is in a fixed location on one side of the bottom of thecontainer, and so during setup at a work site the container must beoriented properly so the outlet port is in a location where the materialcan be received from the outlet port and used in whatever operation isoccurring. Commonly the container includes a chute under the outlet portto direct granular material flowing from the port onto a conveyor beltor the like.

As granular material flows out of the outlet port, the material abovethe port inside the container flows out first and the level of granularmaterial inside the container on the port side thereof above the fixedoutlet port falls until the angle of repose of the particular materialis reached, and material from the opposite side of the container beginsto flow. Thus the loaded container is unbalanced, with more weight onthe side opposite the port, making the container less stable, as thewind force necessary to be exerted on the port side of the container totip the container over is reduced.

Such containers are also known that have a center outlet port in thebottom, however a conveyor or the like is then required to receive thematerial and carry it to a location outside the container. Alternativelythe container can be mounted on legs and a chute can receive thematerial and direct it to a location beside the container, however thismakes containers of the same capacity considerably higher and lessstable.

Stability is also reduced when the container is empty. When filled, theweight of the contents keeps the container in place but when empty,winds or accidental contact with other equipment being moved at the worksite can more easily cause the container to tip over. The stability ofsuch containers is commonly calculated as an empty wind load ratingbased on the wind velocity necessary to tip the container over whenempty.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a transportablecontainer apparatus that overcomes problems in the prior art.

In a first embodiment the present invention provides a transportablecontainer apparatus comprising an elongate container having a centralaxis, and a base attached to a bottom end of the container. Thecontainer and base are substantially symmetrical about the central axis,and the container is oriented substantially vertically with the baseresting on a ground surface when in a working position. The containercomprises an upper container section and a lower container section,where the upper container section has an upper cross-sectional area thatis greater than a lower cross-sectional area of the lower containersection, and the upper container section includes a sloping hopper at abottom thereof, the hopper configured to direct granular material intothe lower container section. An outlet port is defined in a ported wallof the lower container section, and a floor of the container is slopedtoward the outlet port such that granular material stored in thecontainer slides down the floor to the outlet port.

In a second embodiment the present invention provides a transportablecontainer apparatus comprising an elongate container that is orientedsubstantially vertically resting on a ground surface when in a workingposition. An outlet port is defined in a lower portion of a wall of thecontainer, and a floor of the container is sloped toward the outlet portsuch that granular material stored in the container slides down thefloor to the outlet port. A gate is configured to control flow ofmaterial through the outlet port, and a chute assembly is configured toreceive the granular material from the outlet port when the gate is openand deliver the granular material to a chute outlet. The chute assemblyis configured such that the chute outlet can swing through an arc from afarthest right position to a farthest left position.

It is contemplated that the container will typically be cylindrical,thereby avoiding structural issues involved in loading and unloading acontainer with corners. The more centralized unloading that is providedresults in improved stability, and stabilizer legs can further enhancestability. Increased leeway in positioning the container apparatus isprovided by allowing the chute assembly to pivot. A transport trailercan load the apparatus in a number of orientations to facilitatepositioning the chute outlet at a required location, and can be detachedwhen the apparatus is erected.

DESCRIPTION OF THE DRAWINGS

While the invention is claimed in the concluding portions hereof,preferred embodiments are provided in the accompanying detaileddescription which may be best understood in conjunction with theaccompanying diagrams where like parts in each of the several diagramsare labeled with like numbers, and where:

FIG. 1 is a schematic cutaway side view of an embodiment of atransportable container apparatus of the present invention;

FIG. 2A is a top sectional view along line 2-2 in FIG. 1 showing thecylindrical shape of the container of the apparatus;

FIG. 2B is a top sectional view of a possible alternate square shape ofthe container of the apparatus;

FIG. 3 is a schematic cutaway side view of the embodiment of FIG. 1illustrating the flow of granular material out through the outlet port;

FIG. 3A is a schematic cutaway side view of the embodiment of FIG. 1illustrating the flow of granular material out through the outlet portwhen the deflector is removed;

FIG. 4 is a schematic cutaway side view of a transportable containerapparatus of the prior art illustrating the flow of granular materialout through the outlet port;

FIG. 5 is a cut away perspective view of an alternate two chamberembodiment of a transportable container apparatus of the presentinvention with the base removed for easier illustration;

FIG. 6 is a cut away side view of the embodiment of FIG. 5;

FIG. 7A is a cut away perspective view of the gates and the chuteassembly of the embodiment of FIG. 5:

FIG. 7B is a side view of the gates shown in FIG. 7A;

FIG. 7C is perspective view of the chute assembly shown in FIG. 7A inthe stored position;

FIG. 8 is a schematic top view showing the pivoting range of the chuteassembly of FIG. 5;

FIG. 9 is a perspective view of a stabilizer leg for use with anapparatus of the present invention;

FIG. 10 is a perspective view of a lower portion of the embodiment ofFIG. 5 with the base attached and with legs installed thereon as shownin FIG. 9;

FIG. 11 is a side view showing the embodiment of FIG. 5 in a transportposition on a trailer;

FIG. 12 is a side view of the embodiment of FIG. 5 raised to thevertical working position adjacent to the rear end of the trailer;

FIG. 13 is a schematic sectional view along line 13-13 in FIG. 11;

FIG. 14 is a right side view of the embodiment of FIG. 5 with the baseattached;

FIG. 15 is a front view of the embodiment of FIG. 5 with the baseattached;

FIG. 16 is a left side view of the embodiment of FIG. 5 with the baseattached;

FIG. 17 is top view showing two of the embodiment of FIG. 5 raised tothe working position by two trailers at a work site with chute assemblyof each container apparatus oriented in a different orientation withrespect to the trailer;

FIG. 18 is a schematic cutaway side view of an alternate embodiment of atransportable container apparatus of the present invention;

FIG. 19 is a schematic top view showing the pivoting range of the chuteassembly of the embodiment of FIG. 18.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIG. 1 schematically illustrates a cut away side view of an embodimentof a transportable container apparatus 1 of the present invention. Theapparatus 1 comprises an elongate container 3 having a central axis CA,and a base 5 attached to a bottom end of the container 3. Load cells maybe provided between the container 3 and base 5 to indicate how muchmaterial is in the container 3. The illustrated container 3 iscylindrical, as schematically illustrated in the sectional view FIG. 2Aof the container 3, but a container for use with the present inventioncould also he square as schematically illustrated in the sectional viewFIG. 2B of a container 3′, or another shape such as hexagonal,octagonal, or the like where the container 3 and base 5 are symmetricalabout the central axis CA. It is contemplated that a cylindrical shapewill best facilitate manufacture of the apparatus 1. however othershapes could also he used.

The container 3 comprises an upper container section 9 and a lowercontainer section 11. The upper container section 9 has an uppercross-sectional area AU that is greater than a lower cross-sectionalarea AL of the lower container section 11. In a cylindrical container 3as illustrated, the diameter D1 of the upper container section 9 isgreater than the diameter D2 of the lower container section 11. Althoughproportions may vary, in the illustrated container 3 the upper containersection 9 has a diameter D1 that is about twice the diameter D2 of thelower container section 11. The upper container section 9 includes asloping hoppered transition 13 at a bottom thereof, the hopper 13configured to direct granular material into the lower container section11.

The elongate container 3 is oriented substantially vertically with thebase 5 resting on a ground surface 7 when in a working position. Thebase 5 is square and has a width W that is substantially equal to thediameter D1 of the upper container section 9. The apparatus 1 istransported in a horizontal orientation and thus the width of the base 5and the diameter D1 of the upper container section 9 both define themaximum outside dimension when moving along the road. This dimension islimiting in most applications since it is generally desirable to keepthe maximum transport width to a dimension where traffic regulationsrestrict movement of the apparatus 1. The square shaped base 5 willprovide the largest footprint area for the given transport width andthus provide the maximum stability attainable for that dimension.

An outlet port 15 is defined in a ported wall 17 of the lower containersection 11. The floor 19 of the container 3 is conical with all sidessloped toward the outlet port 15 such that granular material stored inthe container 3 slides down the floor 19 to the outlet port 15. Theconical configuration of the floor 19 eliminates corners and alsoprovides a structure that eliminates the need for supports under thefloor 19.

A gate 21 can be opened or closed to control flow of granular materialout of the container 3 through the outlet port 15, and a chute assembly23 is configured to receive the granular material from the outlet port15 when the gate 21 is open and deliver the granular material to a chuteoutlet 25 located beyond the edge of the base 5 so that a conveyor 27 orthe like can he placed on the ground to receive the material and conveysame to a desired location.

The chute assembly 23 can be configured by enclosing the top of samesuch that, when the chute outlet 25 is blocked, granular material, iscontained by the chute assembly 23 when the gate 21 is open. Such aconfiguration allows the gate 21 to be opened wide so that materialflows onto the conveyor 27 as fast as the conveyor takes it away, and ifthe conveyor 27 stops, the material piles up on the conveyor 27 andblocks the chute outlet 25. When the conveyor 27 starts again, flow isresumed. For transport, the chute assembly 23 can he removed, or asdescribed in an alternate embodiment below, pivoted to a stored positioninside the footprint defined by the base 5.

FIG. 3 schematically illustrates the flow of granular material 29 out ofthe container 3 through the outlet port 15. FIG. 4 schematicallyillustrates with arrows F″ the flow of granular material 29X out throughthe outlet port 1.5X of a prior art container 3X. The level of granularmaterial 29, 29X remaining in the respective containers 3, 3X as thematerial flows out is indicated by the dotted lines which are orientedat the angle of repose of the granular material.

In the prior art container 3X of FIG. 4, the granular material 29X flowsdown the ported side 17X of the container 3 and out through the outletport 15X. As can be seen, a significant proportion of the remainingmaterial in the prior art container 3X is located toward the side 31X ofthe container 3X that is opposite the ported side 17X of the container3X. The center of gravity CG′ of the container 3X and the granularmaterial remaining in the container 3X as material flows out thus shiftstoward the side 31X. This shift is indicated by the space S″ between thecentral axis CA″ of the prior art container 3X and the center of gravityCG″ thereof.

FIG. 3 schematically illustrates with arrows F the flow of granularmaterial 29 from the container 3 of the present invention. A deflector30 is added to the bottom of the hopper 13 around the ported side 13A ofthe hopper 13. As material 29 flows down and out of the upper containerportion 9, the material must move down at the inner edge 30A of thedeflector 30. The material 29 thus forms a well 32 with the center ofthe well 32 above the inner edge 30A of the deflector 30. Material flowsinto the well 32 from the ported side 17 and the side 31 of the uppercontainer portion 9 that is opposite the ported side 17. Thus it can beseen that the center of gravity of the material 29 in the uppercontainer portion 9 is nearer the central axis CA than is the case inthe prior art container 3X.

Thus the center of gravity of the of the container 3 and the granularmaterial 29 remaining in the container 3 as material 29 flows out is areduced spacing S from the central axis CA compared to the spacing S″ inthe container 3X of the prior art.

FIG. 3A illustrates the flow of material where there is no deflector.The deflector is added to accentuate the shift of the material 29Y inthe upper container portion 9Y toward the central axis CA′. It can beseen in FIG. 3A that if the deflector 30 shown in FIG. 3 is removed, thematerial 29Y will simply flow from the bottom edge of the hopper 13Ydown along the ported wall 17Y of the lower container section 11 Y tothe outlet port 15Y. The center of the well 32Y would then be above theported wall 17Y of the lower container portion 11Y. Thus amount ofmaterial 29Y in the upper container portion 9Y that is located on theside of the central axis CA′ of container 3Y that is opposite the port15Y is comparatively less than that in the prior art container 3X shownin FIG. 4 and comparatively more than that in the container 3 with thedeflector 30 shown in FIG. 3. Thus the spacing of the center of gravityCG′ from the central axis CA′ in the container 3Y of FIG. 3A is greaterthan the spacing S in the container 3 of FIG. 3, and less than thespacing S″ in the container 3X of FIG. 4.

Thus the container 3Y has improved stability over container 3X becausethe center of gravity is closer to the central axis, and the container 3with deflector 30 has further improved stability over container 3Ybecause the center of gravity is still closer to the central axis.

The more offset the center of gravity CG is from the central axis CA,the less the wind force or accidental contact force required to tip thecontainer over in the offset direction.

It is contemplated that for most applications the diameter D1 of theupper container section 9 will be about 1.5 to about 2.0 times thediameter D2 of the lower container section 11.

Similarly the stability of the apparatus 1 when empty is also increasedby configuring the apparatus 1 such that when the container 3 is empty,a greater proportion of the total weight of the apparatus is in thelower part thereof. In the illustrated apparatus 1, about one half ofthe total weight of the apparatus 1 is located in the bottom one thirdof the height H of the apparatus 1. The base 5 will typically be heavycontaining structural members needed to support the container 3, and theweight of the gate 21 and chute assembly 23 will be located in thebottom third as well. Weight could also be added to the base 5 to bringthe total weight of the apparatus 1 up to a maximum legal weight forhighway travel.

FIGS. 5 and 6 illustrate an alternate embodiment of an apparatus 101 ofthe present invention wherein the container 103 is divided into a firstchamber 140A with a first conical floor 119A sloping to a first outletport 115A, and a second chamber 140B with a second conical floor 119Esloping to a second outlet port 115B. The container 103 is configured tobe mounted on a base as in the apparatus 1 described above. The firstand second chambers 140A, 140B are divided by a wall 114 extending fromthe lower container section 111 upward into the upper container section109 and then sloping laterally to an upright wall 131 of the uppercontainer section 109 that is opposite to the ported wall 117 of thelower container section 111. Alternatively it is contemplated that thedividing wall could go all the way to the top of the container 103 insome applications.

In the illustrated apparatus 101, the first conical floor 119A is abovethe second conical floor 119B and the first and second floors 119A, 119Bslope in the same direction such that the first outlet port 115A isabove the second outlet port 115B in the ported wall of the lowercontainer section 111. The floors 119A, 119B are conveniently providedby formed conical sheets welded into the lower container section 111. Adeflector 130 is provided at the bottom of the hoppered transition 113to direct material from the upper container portion 109 toward thecenter of the apparatus 101. Granular material from the second chamber140B flows through a portal 142 onto the floor 119B.

Corresponding first and second gates 121A, 121B in this apparatus 101are provided above the chute assembly rather than directly over theoutlet ports 115A, 115B. A housing 143 is mounted to the ported side 117of the lower container section 111. over the outlet ports 115A, 115B.Granular material from the first chamber 140A flows out the first outletport 115A to a first clamshell type gate 121A. Granular material fromthe second chamber 140B flows out the second outlet port 115B to asecond clamshell type gate 121B.

The gates 121A, 121B, and chute assembly 123 are illustrated in FIGS.7A, 7B, 7C. A receiver housing 147 of the chute assembly 123 is mountedto the chute housing 143 under the gates 121A, 121B such that materialflowing through either gate is received by the receiver housing 147. Aswivel chute 149 of the chute assembly 123 is pivotally connected to theunderside of the receiver housing 147 such that the swivel chute 149 andthe chute outlet 125 can swing about a vertical pivot axis PA through anarc N from a farthest right position to a farthest left position, asschematically illustrated in FIG. 8. In most applications the arc N willbe about 130-160 degrees which will provide considerable leeway inplacing the apparatus 101 on the ground and still allow the chute outlet125 to be located to deliver material to the desired location adjacentto the apparatus 101.

Thus the chute assembly 123 is configured to receive the granularmaterial from the first outlet port 115A when the first gate 121A isopen and to receive the granular material from the second outlet port115B when the second gate 121B is open and to deliver the granularmaterial to a chute outlet 125. The gates 121A, 121B are operated byextendable cylinders 145. As described above for the apparatus 1, thechute assembly 123 is also configured such that, when the chute outlet125 is blocked, granular material is contained by the chute assembly 123when one of the gates is open. As illustrated in FIG. 7C, the chuteassembly 123 can also be moved to a stored position inside a footprintdefined by the base.

The apparatus 101 also comprises stabilizer legs 151, illustrated inFIGS. 9 and 10. The stabilizer legs 151 comprise a substantiallyhorizontal arm 153 pivotally attached at an inner end 155 thereof to thebase 105 about a substantially vertical arm pivot axis AA. A verticalleg jack 157 is attached to an outer end of the arm 153 to move up anddown to brace the container apparatus against the ground, and an armlock 159 is operative to lock the arm 153 at a selected position withrespect to the arm pivot axis AA. The stabilizer legs are movable aboutthe arm pivot axis AA from the operating position extending beyond thefootprint and contacting the ground, as illustrated in FIGS. 9 and 10,to a stored position inside a footprint defined by the base 105. Astabilizer leg 151 is positioned at each corner of the base 105.

In the illustrated legs 151, the leg jack 157 is a conventional dollyjack such as is used to support the front end of highway trailers and assuch is readily available and economical, and has considerable strength,sufficient to resist tipping of the container apparatus 101. The armlock 159 is provided by a plurality of holes 161 through a lower plate163 spread around the arm pivot axis AA, and a pin 165 that extendsthrough a hole in the leg bracket 167 and one of the holes 161 when theleg 151 is in a desired position such that pivoting about the arm pivotaxis AA is prevented. When the stabilizer legs are extended, the windload rating of the apparatus 101, and the stability thereof, issubstantially increased.

FIGS. 11 and 12 illustrate a trailer 171 releasably attachable to theapparatus 101. A raising bed 173 is pivotally attached at a rear end ofthe trailer 171 and the bed 173 is attachable to the base 105 and lowercontainer section 111 by pins engaging brackets, or by similarengagement mechanisms 175 mounted on the apparatus 101 and configured toengage the raising bed 173 of the trailer 171. An actuator 177 ismounted to the trailer 171 and is operative, when the raising bed 173 ofthe trailer 171 is attached to the apparatus 101, to selectively movethe apparatus 101 between a transport position as illustrated in FIG. 11where the apparatus 101 is supported on the trailer 171 in a horizontalorientation, and a working position as illustrated in FIG. 12 where theapparatus 101 is supported on the ground in a vertical orientation.

Support pads 179 are attached to an upper portion of the container 103and are configured to rest on support posts 181 of the trailer 171 whenthe apparatus 101 is in the transport position. This arrangementsupports the apparatus 101 on the trailer 171 with a wall of the uppercontainer section 109 above the trailer 171 as schematically illustratedin FIG. 13, such that no weight is carried by the wall of the uppercontainer section 109.

In the illustrated apparatus 101, engagement mechanisms 175 are providedon three sides of the apparatus 101. Engagement mechanism 175A is on therear side of the base 105, opposite the chute assembly 123 as seen inFIGS. 14 and 16. Engagement mechanisms 175B and 175C are located on thesides of the base 105 that are right and left of the chute assembly 123,as shown in FIG. 15. The trailer 171 is thus releasably attachable tothe apparatus 101 at a first, second, and third trailer attachmentlocations such that when the apparatus 101 is raised to the workingposition the outlet port and chute assembly 123 will be in one of acorresponding first, second, and third orientation with respect to thetrailer 171. The apparatus 101 can thus be loaded on the trailer 171 ina selected one of three orientations.

FIG. 17 schematically illustrates an example of a pair of theapparatuses 101, 101′ of the present invention, each attached to acorresponding trailer 171, 171′ in a different orientation and being setup at a work site to deliver material into a conveyor 127. Trailer 171is attached to engagement mechanism 175C while trailer 171′ is attachedto engagement mechanism 175A. The apparatuses 101, 101′ are locateddiagonally adjacent to each other, but the plurality of attachmentlocations and corresponding chute assembly orientations allows the chuteassemblies 123, 123′ to discharge the container contents into the sameconveyor 127 located generally between the apparatuses 101. Typicallythe trailers 171, 171′ will be detached from the apparatuses and movedaway from the work site.

FIG. 17 also shows how the stabilizer legs 151 can be moved to aselected location and jacked down to stabilize the apparatus. As can heseen the legs 151 are positioned where there is room, and where there isno room any leg can simply be left in the stored position.

FIGS. 18 and 19 schematically illustrate a transportable containerapparatus 201 comprising an elongate container 203 that is orientedsubstantially vertically resting on a ground surface 207 when in aworking position. An outlet port 215 is defined in a lower portion of awall of the container 203 and a conical floor 219 of the container 203is sloped toward the outlet port 215 such that granular material storedin the container 203 slides down the floor 119 to the outlet port 215.

A gate 221 opens and closes to allow granular material to flow from thecontainer 203 through the outlet port 215. A chute assembly 223 isconfigured to receive the granular material from the outlet port 215when the gate 221 is open and deliver the granular material to a chuteoutlet 225. The chute assembly 223 is configured such that the chuteoutlet 225 can swing through an arc N from a farthest right position toa farthest left position. In the illustrated chute assembly the angle Nis about 180 degrees, and for most applications it is contemplated thatan angle N of greater than about 130 degrees will provide satisfactoryleeway in positioning the apparatus 201 to deliver granular materialtherefrom into a desired location.

As described above the chute assembly 223 is enclosed such that, whenthe chute outlet 225 is blocked, granular material is contained by thechute assembly 223 when the gate 221 is open. Stabilizer legs could alsobe provided as described above.

The present invention thus provides a transportable container apparatuswith more centralized unloading and resulting improved stability.Stabilizer legs can be added to further enhance stability. A pivotingchute assembly can also provide increased leeway in positioning thecontainer apparatus. The apparatus can be configured to attach top atransport trailer in number of different orientations to facilitatepositioning the chute outlet at a required location.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous changes and modifications willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly, all such suitable changes or modificationsin structure or operation which may be resorted to are intended to fallwithin the scope of the claimed invention.

We claim:
 1. A transportable container apparatus comprising: an elongatecontainer having a central axis, and a base attached to a bottom end ofthe container, wherein the container and base are substantiallysymmetrical about the central axis, and wherein the container isoriented substantially vertically with the base resting on a groundsurface when in a working position; the container comprising an uppercontainer section with upper walls substantially parallel to the centralaxis and a lower container section with lower walls substantiallyparallel to the central axis, where the upper container section has anupper cross-sectional area that is greater than a lower cross-sectionalarea of the lower container section, and the upper container sectionincludes a sloping hopper at a bottom thereof, the hopper configured todirect granular material into the lower container section; an outletport defined in a ported wall of the lower container section, the outletport oriented substantially vertically when the container is in theworking position; and wherein a floor of the container is sloped towardthe outlet port such that granular material stored in the containerslides down the floor to the outlet port.
 2. The apparatus of claim 1wherein the container is substantially cylindrical, and wherein adiameter of the upper container section is greater than a diameter ofthe lower container section.
 3. The apparatus of claim 2 wherein thediameter of the upper container section is about 1.5 to about 2.0 timesthe diameter of the lower container section.
 4. The apparatus of claim 2wherein the base is substantially square and has a width substantiallyequal to a diameter of the upper container section.
 5. The apparatus ofclaim 1 wherein the floor is conical.
 6. The apparatus of claim 1wherein the container is divided into a first chamber with a first floorsloping to a first outlet port, and a second chamber with a second floorsloping to a second outlet port.
 7. The apparatus of claim 6 wherein thefirst floor is above the second floor and the first and second floorsslope in the same direction such that the first outlet port is above thesecond outlet port in the ported wall of the lower container section. 8.The apparatus of claim 6 wherein the first and second floors areconical.